Definition
A control valve is a valve specifically designed for continuous, precisely modulated flow control (adjusting its opening position across a range in response to a process control signal) rather than the simple on/off switching a solenoid valve typically provides, commonly paired with a positioner to translate a control signal into an accurate valve position.
Key facts
- Provides continuous, modulated flow control across a range, distinct from a solenoid valve's typical on/off switching.
- Responds to a process control signal, often as part of a closed-loop process control scheme (e.g., regulating flow to maintain a level or temperature setpoint).
- Typically paired with a positioner, which translates the control signal into a precise, verified valve position.
- Sizing and characteristic (linear, equal-percentage) must match the process requirement for effective control across the operating range.
How does Control valve work or appear?
A control valve continuously adjusts its opening position (anywhere from fully closed to fully open) in response to a varying process control signal, providing the modulated flow control needed to maintain a process variable such as level, flow, pressure, or temperature at a desired setpoint.
What should technicians inspect for Control valve?
A control valve provides continuous, precisely modulated positioning across a range, typically paired with a positioner for accuracy. A solenoid valve instead typically provides simple on/off switching via electromagnetic actuation, well suited to applications needing a binary open/closed state rather than modulated flow control.
FAQ
Frequently asked questions
How does a control valve influence a process variable?
It influences it by continuously adjusting its opening position in response to a process control signal, providing modulated flow control rather than simple on/off switching.
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